1. Field of the Invention
The present invention relates to a routing method in an ad hoc network formed by a plurality of mobile terminals, and mobile terminals for implementing the routing method.
2. Description of the Related Art
A method in an ad hoc network for identifying an uncooperative terminal and excluding the identified uncooperative terminal, thereby avoiding being affected by the uncooperative terminal has been known.
Here, an uncooperative terminal means a selfish user's mobile terminal which does not relay packets generated by other mobile terminals but transmits packets generated by itself, or a malicious user's mobile terminal which intentionally discards packets generated by other mobile terminals.
With reference to FIGS. 1 and 2, an example of a conventional method for avoiding being affected by an uncooperative terminal in an ad hoc network will be described.
With FIG. 1, an example of using a “watchdog technique” for monitoring every packet in radio-wave-reaching areas, utilizing radio characteristics, in an ad hoc network formed by a plurality of mobile terminals #A to #F will be described.
As shown in FIG. 2, in step S1001, the mobile terminals #A to #F forming the ad hoc network monitor every packet in their respective radio-wave-reaching areas #A to #F.
In step S1002, when a mobile terminal detects an uncooperative terminal, it reports information on the uncooperative terminal throughout the ad hoc network.
In step S1003, all the mobile terminals in the ad hoc network share the reported information on the uncooperative terminal, and exclude the uncooperative terminal from the ad hoc network.
The conventional method, however, identifies an uncooperative terminal and excludes the identified uncooperative terminal from the ad hoc network, thereby, thereafter, to avoid being affected by the uncooperative terminal.
That is, the conventional method excludes an uncooperative terminal after identifying it, thus having the problem that it allows selfish communication of the uncooperative terminal (is affected by the uncooperative terminal) before exclusion.
Also, the conventional method has the problem that since a plurality of mobile terminals forming an ad hoc network need to monitor every packet in their respective radio-wave-reaching areas, a processing load is increased.
Also, the conventional method has the problem that since information on an uncooperative terminal is propagated throughout an ad hoc network, a network load is increased.
In addition, since information on an uncooperative terminal is shared and processed by all the mobile terminals in an ad hoc network, there is the problem of increased processing areas.